Novel diallyl-containing fluoropolyether compound and method for producing the same

Abstract

To provide: a novel fluoropolyether compound that does not contain a C7 or larger linear perfluoroalkyl group, that lacks the potential to decompose into bioaccumulative and toxic perfluorooctanoic acid, and that has two polymerizable unsaturated bonds in each molecule; and a method for producing the same.SOLUTION: A diallyl fluoropolyether compound is represented by general formula (where b is an integer equal to or greater than 2, and a and c are integers satisfying a+c≤28). The compound is produced by reacting a polyfluoropolyether diol represented by the general formula HOCH2CF(CF3)[OCF2CF(CF3)]aO(CF2)bO[CF(CF3)CF2O]cCF(CF3)CH2OH (where b is an integer equal to or greater than 2, and a and c are integers satisfying a+c≤28) with at least 2.2-fold molar equivalents, with respect to the polyfluoropolyether diol, of an allyl halide in the presence of a phase transfer catalyst in an aqueous solution of an alkali metal hydroxide.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a novel fluorine-containing polyether compound and a process for producing the same, more specifically to a novel fluorine-containing polyether compound having two polymerizable unsaturated bonds in one molecule and a process for producing the same. [Background technology]

[0002] Patent Document 1 describes the general formula R1R2C=CR3-Z-CR4=CR5R6 (wherein R1, R2, R3, R4, R5 and R6 are the same or different and are H or a C1-C5 alkyl group; Z is a C1-C alkyl group optionally containing an oxygen atom; 18 The document describes a fluoroalkylene compound represented by the formula (I), which is a linear or branched alkylene or cycloalkylene group, and is preferably at least partially fluorinated or a (per)fluoropolyoxyalkylene group. This compound may contain a linear perfluoroalkyl group of C7 or more, and may decompose into perfluorooctanoic acid, which is bioaccumulative and toxic. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5057657 [Patent Document 2] Japanese Patent Publication No. 63-253044 [Patent Document 3] Special Publication No. 1-57125 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a novel fluorine-containing polyether compound having two polymerizable unsaturated bonds in one molecule, which does not contain a linear perfluoroalkyl group of C7 or more and is not likely to decompose into bioaccumulative and toxic perfluorooctanoic acid, and a method for producing the same. [Means for solving the problem]

[0005] The object of the present invention is to provide a compound of the general formula This can be achieved by a diallyl fluorine-containing polyether compound represented by the formula TIFF2025124949000001.tif25168 (wherein b is an integer of 2 or more, and a and c are integers such that a+c=28 or less).

[0006] Such a diallyl fluorine-containing polyether compound has the general formula HOCH2CF(CF3)〔OCF2CF(CF3)〕 a O(CF2) b O〔CF(CF3)CF2O〕 c CF(CF3)CH2OH [II] (where b is an integer of 2 or more, and a and c are integers such that a+c=28 or less) is reacted with 2.2 molar equivalents or more of allyl halide relative to the polyfluoropolyether diol in an aqueous alkali metal hydroxide solution in the presence of a phase transfer catalyst. [Effects of the Invention]

[0007] The diallyl fluorine-containing polyether compound according to the present invention is a terminally bifunctional monomer having two polymerizable functional groups in the molecule, and therefore can be effectively used as a crosslinking agent monomer for various fluorine-containing resins, which enables crosslinking in a three-dimensional structure, and has the excellent effect of enabling improvements in various physical properties such as hardness, strength, heat resistance, weather resistance, and chemical resistance of the resulting crosslinked resins, etc. Furthermore, since it has a large number of fluorine atoms, it has excellent thermal stability and chemical stability, as well as good optical properties and surfactant properties. [Brief explanation of the drawings]

[0008]

Figure 1

[0009] Diallyl fluorine-containing polyether compounds represented by general formula [I] In TIFF2025124949000002.tif25168, b is 2 or more, preferably an integer of 2 to 6 from the viewpoint of easy availability of raw materials, and a and c are each equal to or less than a+c=28, preferably an integer of 20 or less from the viewpoint of ease of production, and a and c can be 0. The compound represented by general formula [I] is a novel compound, and is characterized by having two polymerizable allyl groups at its terminals.

[0010] The diallyl fluorine-containing polyether compound [I] is represented by the general formula HOCH2CF(CF3)〔OCF2CF(CF3)〕 a O(CF2) b O〔CF(CF3)CF2O〕 c CF(CF3)CH2OH [II] (wherein b is an integer of 2 or more, and a and c are integers such that a+c=28 or less) is reacted with an allyl halide in an amount of 2.2 times or more, preferably about 2.2 to 3.0 times the molar equivalent of the polyfluoropolyether diol, in an aqueous alkali metal hydroxide solution in the presence of a phase transfer catalyst.

[0011] The polyfluoropolyether diol [II] can be obtained by a known technique, and is generally prepared by reacting the corresponding polyfluoropolyether difluoride represented by the following general formula [III] in an alcohol or ether solvent. FOCCF(CF3) [OCF2CF(CF3)] a O(CF2) b O〔CF(CF3)CF2O〕 c CF(CF3)CFO (III) with a reducing agent, preferably in an alcohol solvent in the presence of sodium borohydride or potassium borohydride, to obtain the polyfluoropolyether difluoride (Patent Document 2).

[0012] The production of the diallyl fluorine-containing polyether [I] is carried out in a two-layer system consisting of an organic layer containing the polyfluoropolyether diol [II] and an allyl halide, and an aqueous layer containing an alkali metal hydroxide and a phase transfer catalyst.

[0013] Examples of the allyl halide include allyl iodide, allyl bromide, and allyl chloride, and allyl bromide is preferably used from the viewpoints of reactivity, operability, and availability. For the introduction of diallyl groups, the allyl halide is used in an amount of 2.2 times or more molar equivalents, preferably 2.2 to 3.0 times molar equivalents, relative to the polyfluoropolyether diol.

[0014] As the alkali metal hydroxide, lithium hydroxide, sodium hydroxide, potassium hydroxide, etc. are used, and preferably sodium hydroxide is used in the form of an aqueous solution. The alkali metal is used to convert the hydroxyl groups of the polyfluoropolyether diol into alkali metal salts.

[0015] The phase transfer catalyst may be a quaternary ammonium salt such as tetramethylammonium chloride, tetramethylammonium bromide, tetraethylammonium chloride, tetraethylammonium bromide, tetrapropylammonium chloride, tetrapropylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium bromide, hydrogenated tetrabutylammonium sulfate, or hydrogenated tetrahexylammonium sulfate, preferably hydrogenated tetrabutylammonium sulfate. The phase transfer catalyst is used in a molar ratio of about 0.1 to 0.4 times the polyfluoropolyether diol.

[0016] In the reaction, a compatible organic solvent can be used to improve the reactivity. As the compatible organic solvent, a non-polar solvent having no active hydrogen is used, specifically, 1,2-dimethoxyethane, 1,2-diethoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, etc. is used, and preferably, 1,2-dimethoxyethane, which is also used as a reaction solvent for polyfluoropolyether diol [II], etc. is used.

[0017] The reaction proceeds over a wide range of temperatures, from room temperature to about 90°C, but from an economical point of view, a sufficient reaction conversion rate is obtained between room temperature and about 40°C.

[0018] The obtained diallyl fluorine-containing polyether compound is effectively used as a crosslinking agent monomer for various fluorine-containing resins, such as tetrafluoroethylene-perfluoro(methyl vinyl) copolymer, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene-hexafluoroethylene copolymer, vinylidene fluoride-tetrafluoroethylene-perfluoro(methyl vinyl ether), etc. [Example]

[0019] The present invention will now be described in detail with reference to examples, although the present invention, including its effects, is not limited to these examples.

[0020] Example Process (1) TIFF2025124949000003.tif27168 Under a nitrogen atmosphere, 2,5,10-tris(trifluoromethyl)-3,6,9-trioxaundecanoic acid difluoride (71.8 GC% - 1.0 kg, 1.21 mol) was slowly added dropwise to methanol (752 g) while maintaining the internal temperature below 40 °C using an ice bath. After the addition was complete, the ice bath was removed and the mixture was stirred at room temperature for 2 hours. Tap water (150 mL) was added, and the mixture was stirred for 1 hour. After allowing to stand for 30 minutes, the lower layer was recovered. The pH was adjusted to 5 with 3 wt% NaHCO3 solution and washed twice with tap water (300 mL). The lower layer was dried over magnesium sulfate, and the solids were removed by pressure filtration, yielding 948.8 g (71.6 GC%) of the distillation raw material. Distillation was carried out using a column packed with 30 cm of Heli-Pack No. 2, yielding 602.6 g (99.3 GC%, 88.0%) of the target product as a colorless, transparent liquid at room temperature. From the H, F-NMR below, this compound was determined to be 4,7,12-tris(trifluoromethyl)-2,5,8,11,14-pentaoxapentadecane dimethyl ester represented by the above formula. H-NMR (Acetone-d6, TMS); δ4.12(O CH 3) F-NMR (Acetone-d6); ppm -78.28( CF 2CFCF3O) -79.05(CF2CF CF 3O) -81.46(CH2CF CF 3O x 2) -83.27~-85.23(O CF 2 CF 2O) -130.29(CF2 CF CF3O x 2) -144.14(CH2 CF CF3O)

[0021] Process (2) TIFF2025124949000004.tif24168 Under a nitrogen atmosphere, sodium borohydride (SBH) (40.9 g, 1.08 mol) was added to isopropanol (860.1 g). While cooling in an ice bath, 4,7,12-tris(trifluoromethyl)-2,5,8,11,14-pentaoxapentadecane dimethyl ester (99.3 GC% - 590.0 g, 0.94 mol) was slowly added dropwise. After the addition was complete, the mixture was stirred for 20 hours. While cooling in an ice bath, 3M hydrochloric acid (350.0 g) was added dropwise to adjust the pH to 1. After stirring, the mixture was transferred to a separatory funnel, tap water (100 mL) was added, and the mixture was allowed to stand for 30 minutes. The lower layer was then collected. The lower layer was neutralized to pH 6 by dropwise addition of 5 wt% NaHCO3 aqueous solution (120.0 g), transferred to a separatory funnel, and allowed to stand for 30 minutes, after which the lower layer was recovered. After drying over magnesium sulfate, the solids were removed by pressure filtration. Purification was carried out by simple distillation, yielding 325.9 g (88.5 GC%, 53.8% yield) of the target product as a colorless, transparent, highly viscous liquid at room temperature. From the H,F-NMR below, this compound was determined to be 2,5,10-tris(trifluoromethyl)-3,6,9-trioxaundecanediol represented by the formula above. H-NMR (Acetone-d6, TMS); δ4.25( CH 2OH) 5.31(CH2 OH ) F-NMR (Acetone-d6); ppm -77.95( CF 2CFCF3O) -78.98(CF2CF CF 3O) -81.10(CH2CF CF 3O x 2) -83.20~-86.14(O CF 2 CF 2O) -134.12(CF2 CF CF3O x 2) -144.08(CH2 CF CF3O) MS(CI) m / z: 561(MH+ )

[0022] Process (3) TIFF2025124949000005.tif27168 Under a nitrogen atmosphere, 1,2-dimethoxyethane (162.5 g) was added to SBH (6.92 g, 0.18 mol). The internal temperature was adjusted to approximately 41 °C using an oil bath, and 4,7,12-tris(trifluoromethyl)-2,5,8,11,14-pentaoxapentadecane dimethyl ester (99.3 GC%, 100.0 g, 0.16 mol) was slowly added dropwise. After the addition was complete, the mixture was stirred for 22 hours. While cooling in a water bath, 3 M hydrochloric acid (60.0 g) was added dropwise to adjust the pH to 1, followed by stirring. The mixture was then transferred to a separatory funnel, tap water (100 mL) was added, and the mixture was allowed to stand for 30 minutes, after which the lower layer was collected. The lower layer was neutralized to pH 6 by dropwise addition of 5 wt% NaHCO3 aqueous solution (20.0 g), transferred to a separatory funnel, and allowed to stand for 30 minutes, after which the lower layer was recovered. After drying over magnesium sulfate, the solid was removed by pressure filtration to obtain 129.8 g (33.3 GC%, reaction yield 47.5%) of a 1,2-dimethoxyethane solution of 2,5,10-tris(trifluoromethyl)-3,6,9-trioxaundecanediol.

[0023] Process (4) TIFF2025124949000006.tif21168 Under a nitrogen atmosphere, tetrabutylammonium hydride sulfate (TBAHS, 19.6 g, 0.058 mol) was added to a 1,2-dimethoxyethane solution of 2,5,10-tris(trifluoromethyl)-3,6,9-trioxaundecanediol (34.9 GC%, 454.5 g, 0.29 mmol) obtained in step (3) above, while cooling in a water bath. A 30% aqueous solution of NaOH (95.1 g, 0.72 mol) was added dropwise and stirred for 30 minutes. Allyl bromide (82.9 g, 0.69 mol) was then added dropwise and stirred for 20 hours. The mixture was allowed to stand for 30 minutes to separate, and the upper layer was collected and washed twice with tap water (200 mL). The lower layer was collected. After drying over magnesium sulfate, the solid was removed by pressure filtration, yielding 315.8 g (29.4 GC%) of the distilled raw material. Purification was carried out by simple distillation, yielding 25.4 g (94.0 GC%, 14.0% yield) of the target product, which was a colorless, transparent liquid at room temperature. From the H,F-NMR below, this compound was determined to be 6,9,14-tris(trifluoromethyl)-4,7,10,13,16-pentaoxanona-1,18-didekene [OXF3PO-DAE] represented by the formula above. H-NMR (Acetone-d6, TMS); δ 4.25( CH 2OH), 5.31(CH2 OH ) F-NMR (Acetone-d6); ppm -79.02(CF2CF CF 3O) -80.87( CF 2CFCF3O) -81.47(CH2CF CF 3O x 2) -84.14~-86.20(O CF 2 CF 2O) -131.93(CF2 CF CF3O x 2) -144.15(CH2 CF CF3O) MS(EI) m / z: 640

[0024] In addition, OXF3PO-DAE could also be obtained by a similar method using 2,5,10-tris(trifluoromethyl)-3,6,9-trioxaundecanediol obtained by the method in step (2) above.

[0025] Reference examples 1~3 A fluorine-containing copolymer having a tetrafluoroethylene / perfluoro(methyl vinyl ether) copolymerization ratio of 68 / 32 mol% and an iodine and bromine content of 0.4 wt% was prepared according to the method described in Patent Document 3. 5 parts by weight of OXF3PO-DAE and 2 parts by weight of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane (Perhexa 25B, a product of Nippon Oil & Fats) were added to 100 parts by weight of this copolymer, and the mixture was kneaded on a two-roll mill at a temperature of 30 to 100°C. The kneaded mixture was press-vulcanized (primary vulcanization) at 180°C for 15 minutes (Reference Example 1), 160°C for 20 minutes (Reference Example 2), and 150°C for 30 minutes (Reference Example 3).

[0026] The vulcanization torque of the obtained vulcanizate was measured. Vulcanization torque: Alpha Technologies RPA2000, 180°C, 160°C and 150°C, Measured for 30 minutes

[0027] The results obtained are shown in the table below and in FIG. TIFF2025124949000007.tif59166

[0028] From the above results, it was confirmed that an increase in vulcanization torque was observed under all conditions, 180°C, 160°C, and 150°C, and that OXF3PO-DAE can function as a cross-linking agent for fluoropolymers. [Industrial Applicability]

[0029] The novel diallyl fluorinated polyether compound of the present invention has a low refractive index due to its high fluorine content, and can be used as an anti-reflection film for displays, etc., or as a cladding material for optical fibers, etc. Furthermore, by taking advantage of its surfactant properties, it can be used as various release coating agents, various surface coating agents, surface modifiers, and water and oil repellents.

Claims

1. general formula (wherein b is an integer of 2 or more, and a and c are integers such that a+c=28 or less)

2. general formula HOCH 2 CF(CF 3 )〔OCF 2 CF(CF 3 )〕 a O(CF 2 ) b O〔CF(CF 3 )CF 2 O〕 c CF(CF 3 )CH 2 OH 〔II〕 (wherein b is an integer of 2 or more, and a and c are integers such that a+c=28 or less), is reacted with 2.2 molar equivalents or more of allyl halide relative to the polyfluoropolyether diol in an aqueous alkali metal hydroxide solution in the presence of a phase transfer catalyst.

3. 3. The process for producing a diallyl fluorinated polyether according to claim 2, wherein the phase transfer catalyst is a quaternary ammonium salt.

4. 4. The process for producing a diallyl fluorine-containing polyether according to claim 3, wherein the quaternary ammonium salt is tetramethylammonium bromide, tetraethylammonium chloride, tetrapropylammonium chloride, tetrabutylammonium hydrogensulfate or tetrahexylammonium hydrogensulfate.

5. 3. The process for producing a diallyl fluorinated polyether according to claim 2, wherein the alkali metal hydroxide is sodium hydroxide.

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